Retractile roller assemblage



Jul 10, 1951 L EDHLUND 2,559,856

RETRACTILE ROLLER ASSEMBLAGE Filed Oct. 22, 1946 //v VE/V TOR Z 50/71 U/Vfl Ar romvfy Patented July 10, 1951 RETRACTILE ROLLER ASSEMBLAGE Leslie J. Edhlund, St. Paul, Minn., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application October 22, 1946, Serial No. 704,863

1 Claim.

This invention relates to retractile roller assemblages and. more particularly to such an assemblage for rollable ladders.

An object of this invention is the provision of a roller assemblage having a simple and reliable automatic brake arrangement for rollable ladders effective when the ladder is unoccupied to maintain the ladder rails out of contact with the floor so that the ladder can be readily moved and will permit, when the ladder is occupied, the rails thereof to contact the floor to prevent movement of the ladder.

In accordance with the above object, this invention contemplates, in one embodiment thereof, a retractile roller assemblage having an automatic brake arrangement for rollable ladders in which a combined bracket and housing for a roller has a slide plate fixed thereon adapted to slide in a slideway member fixed to the outer side of the ladder rail at its lower end adjacent the floor, one assemblage being similarly arranged on each of the spaced ladder rails. Encircling a guide rod fixed at its lower end to an arm at the upper end of the roller bracket and its upper end guided in an apertured bracket fixed to the ladder rail is a compression spring abutting at 0pposite ends the bracket arm and the apertured bracket. The normal action of the spring is such that when a persons weight is not on the ladder, the ladder is supported on the rollers with the rails raised from the fioor so that the ladder can be roller freely, but when a persons weight is placed upon the ladder, the springs are compressed and the ladder moves downwardly to engage rubber anti-skid pads, attached to the bottom end faces of the ladder rails, with the floor, thus preventing the ladder from rolling while a person is supported on it. Upon the persons weight being removed from the ladder, the springs automatically raise the ladder off the floor, whereupon it can be freely rolled.

Other objects and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing, in which Fig. 1 is a fragmentary view in front elevation of a rollable ladder equipped with one embodiment of the retractile roller assemblages of this invention, the ladder being shown supported on the rollers with the ladder rails raised from the floor;

Fig. 2 is an enlarged end view of the assemblage looking at the right end of Fig. 1;

Fig. 3 is an enlarged fragmentary view, partly in section, of the right hand roller assemblage of Fig. 1; and

Fig. 4 is an enlarged plan sectional view taken on the line 4-4 of Fig. 3.

Referring to the drawing in detail, and particularly to Fig. 1, the retractile roller assemblage of this invention is shown applied to a conventional form of rollable ladder, indicated fragmentarily at I0, and comprising two side rails lI--H and a series of cross treads or rungs I2 supported thereby, of which only the lowest is shown, the remainder of the ladder and the means for supporting the upper end thereof being omitted since they are not necessary to an understanding of this invention.

The retractile roller assemblages of this invention, indicated in general at l3, are carried upon the outer side faces of the rails H--H adjacent their lower ends. Each assemblage It comprises a combined bracket and housing 14 for a roller ll, which is mounted within the housing for free rotation on an axle l8 carried by the housing. Attached, as indicated at l9l9 (Figs. 3 and 4) to the housing It at its left side is a slide plate 20 adapted to freely slide in spaced slideways 2l2i formed on a plate 22 fixed, as indicated at 23-23, to the outer side face of the ladder rail H. An arm 24, integral with the upper end of the slide plate 20, extends over the adjacent upper ends of the spaced slideways 2 l2l of the plate 22 and thus limits the upward movement of the plate 22 relative to the slide plate 20. Fixed to the arm 24 and extending perpendicular to the direction of movement of the slide plate 20 is a rod 26 having its upper end guided in a bracket 2'! attached, as indicated at 28, to the outer side face of the ladder rail I. Surrounding the rod 25, withits opposite ends abutting the bracket 21 and the arm 2% is a coiled compression spring 29, which normally acts to raise the bracket 2'! and thereby the ladder rail H to the position shown in the drawing with the roller i1 supported on the floor. In such a position of the ladder, anti-skid rubber pads or feet 30 fixed to the bottom end faces of the ladder rails are out of engagement with the floor. The springs 29 of each assemblage are of such tension that, by their combined action, the weight of the ladder IE is overcome when a persons weight is not upon the ladder, but when a predetermined portion of the weight of a user is put on the ladder, such as the user initially placing one foot upon the lowermost rung l2 and following with his entire weight, the springs 29 will be compressed and the ladder ID will move downward to engage the anti-skid pads 30 with the floor to the position shown in broken outline in Fig. 3, thus insuring that the ladder will not roll while a user is mounting the ladder or after his entire weight is thereon. When the users weight is removed from the ladder, the springs automatically raise the ladder off the floor, whereupon it can be freely rolled.

What is claimed is:

A retractile roller assemblage in combination with a ladder having rails comprising a plate attached to a face of a ladder rail adjacent its lower end and of substantially the width of said rail and having the side edge portions thereof shaped to provide channel shaped slideways, a slidable plate having opposite side edges engaging said slideways and having a portion directed transversely outwardly therefrom above said channel shaped slideways and engageable therewith for limiting the downward movement of said slidable plate, a roller bracket secured to said slidable plate, a roller axially supported on said bracket for rolling on the fioor, a member secured to said rail having a guide aperture spaced longitudinally from said slideways, a 25 guide element secured to said transversely directed portion of said slidable plate and extending through said aperture, and a resilient member surrounding said guide element for urging said slidable plate to a position where said roller extends below said rail.

LESLIE J. EDHLUND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,155,607 Neller Oct. 5, 1915 1,527,239 Vaughan et a1 Feb. 24, 1925 1,967,332 Smith 'July 24, 1934 2,176,551 Solem Oct. 17, 1939 FOREIGN PATENTS Number Country Date 20,673 Great Britain 1911 210,727 Germany Oct. 8, 1908 

